A pesticide is a substance or compound which is directed to the control, either by destroying or mitigating a pest. There are different kinds or classes of pesticides, and they can have synthetic origin, natural origin, or they can also be biological agents.
The use of pesticides is widely adopted worldwide and more particularly, they are routinely used in different crops, in order to control the different types of pests that can affect the production.
In the present invention, the focus is directed to organic compounds which can have a pesticide effect on a pest, such as fungi, bacteria, insects, nematodes, or other type of pest that can affect a particular crop, such as fruits, vegetables, nuts, or any other type of agricultural product.
More specifically, in the case of fruits, different kinds of pesticides are used, and the application of these compounds or agents, when water soluble pesticides are considered, is through the use of oils or waxes which allow the active ingredient (pesticide) to remain attached to the fruit even when water is used for irrigation, or when rain falls, in which cases a water soluble pesticide would be washed away, and its effect would be lost in the short term.
In the case when a wax or oil is used as an adjuvant for the application of a particular pesticide, these molecules with biocide activity remain present in the fruit as it is harvested and further processed.
A particular case is the use of fruit products for industrial processing, such as in the case of natural juices or juice extracts or sauces, which consider the processing of the whole fruit. In this type of industrial processing scenario, when the whole fruit is processed, the pesticides that were present in the fruit coating will remain present in the final processed product, such as for example a juice or a fruit extract, tomato sauce, or even wine in the case of grapes treated with a pesticide.
Therefore, processing of liquid foodstuffs for removal of pesticides that can be present therein is an always present requirement and necessity in order to improve the safety of foodstuffs.
In this document, the description of the scope of the invention is usually exemplified by references to the wine industry, nevertheless, this must not be understood as a limitation of the invention to said industry, since the compounds, compositions and methods of the present invention can be applied to a wide variety of liquid foodstuffs or beverages. Therefore, the terms liquid foodstuff or beverage must be understood in their widest meaning, such as for example, but not limited to, fruit juices, plant juices or extracts, fermented beverages, alcoholic fermented beverages, such as wine, beer, cider, sparkling wine, ale, rye beer, chicha, sake, pulque; or distilled alcoholic beverages such as whisky, whiskey, vodka, korn, brandy, cognac, vermouth, pisco, armagnac, branntwein, singani, arak, ouzo, pastis, sambuca, grappa, orujo, aguardiente, ron, cachaga, tequila, mezcal, among many other liquid foodstuffs or beverages containing phenolic compounds which, depending on the requirements of the industry or the customer, should be removed from the liquid foodstuff or beverage.
A new area being developed is that of smart polymers that have many advantages and applications. Particularly, these smart polymers can be used to trap phenolic compounds with high selectivity according to the requirements of a particular industry. Other advantages that these polymers have is their easy synthesis and characterization in addition to being environmentally and biologically benign, easy to separate from the final product and a selectivity that can be altered by changing the functional group of the polymers.
One way to address the above problems is through the detection, quantification and removal of unwanted substances using smart polymers. The use of branched polymers as opposed to the traditional linear ones, on the removal of unwanted substances, could largely improve the efficiency and specificity of practices where traditional methods are employed.
The procedure employed for the development of these smart polymers consisted on the following: The identification of target phenolic compounds with biocide activity, the synthesis and chemical characterization of an array of smart polymers based on their potential binding capabilities against phenolic compounds, the screening of the interaction between the polymers and selected phenolic compounds via liquid chromatography and UV-Vis spectrometry, and testing of the polymers in real food matrices (e.g. wine).
Thus, the problem to be solved by the present invention is removing selectively unwanted compounds from a liquid foodstuff or beverage, with a high yield, and a broad working pH range, and the solution proposed in the present invention is providing compounds or compositions for selective adsorption of compounds which affect negatively the quality of a liquid foodstuff or beverage, or more particularly, resolving the problem of the presence of pesticides in the end product.
The present invention is directed to compounds which have shown that adsorb selectively specific phenolic compounds which are routinely used as pesticide, or more particularly fungicides.
In order to solve the proposed technical problem, different polymers were designed, tested, and screened which would have the higher selectivity and yield for a set of identified specific compounds. These polymers resulted to be specific forms of polyaniline, and polyamidoamine materials functionalized with polyaniline polymers.
Polyaniline is a conducting polymer formed by combination of aniline monomers. The polymerized aniline monomers can be found in different oxidation states, where the fully reduced state is known as leucoemeraldine, while the fully oxidized state is known as (per)nigraniline. The intermediate state, emeraldine, has two forms, one the emeraldine base (PANI-EB) is the neutral form, and emeraldine salt PANI-ES) is the protonated form. The use of polyaniline polymers has been primarily directed to semiconductive devices, or electric devices; its use in batteries or in the conversion of chemical energy to electrical energy, whereas the application of polyaniline materials in the food industry has been limited to the use of the compound as a sensor, for example for evaluating the toxicity of a food product.
Other part of the molecules considered in this present invention are dendrimers. The dendrimers correspond to a repetitively branched molecule based on polymers. A dendrimer is usually symmetric around its core and might adopt a spherical or ellipsoidal shape. There are high and low molecular weight dendrimers, depending on the amount and length of branches. These molecules are typically used as a core for a larger molecule which would have specific features and functions depending on the functional groups that can be added to the surface of a dendrimer.
Dendrimers can also be classified in terms of its generation. The generation corresponds to the number of repeated branching cycles that are performed during its synthesis. The higher the generation of a dendrimer, the higher the number of exposed functional groups in its surface.
In particular, the present invention is directed to polyamidoamine (PAMAM) dendrimers. The core of PAMAM is a diamine (commonly ethylenediamine), which is reacted with methyl acrylate, and then another ethylenediamine to make the generation-0 (G-0) PAMAM. Further cycles of reactions will then render higher PAMAM generations.
The use of PAMAM dendrimers has seen a wide variety of applications. For example, PAMAM materials have been used in pharmaceutical compositions as carriers, as substrate for analyses or detection of compounds, associated with nucleic acids for therapeutic purposes.